[gcc(refs/users/marxin/heads/marxin-gcc-benchmark-branch)] rs6000: Fix infinite loop building ghostscript and icu [PR93658]

[Martin Liska]

https://gcc.gnu.org/g:b82d426662469ee8b78ec7e8f74abe950485c9d5

commit b82d426662469ee8b78ec7e8f74abe950485c9d5
Author: Peter Bergner <bergner@linux.ibm.com>
Date:   Thu Feb 20 11:08:02 2020 -0600

    rs6000: Fix infinite loop building ghostscript and icu [PR93658]
    
    Fix rs6000_legitimate_address_p(), which erroneously marks a valid Altivec
    address as being invalid, which causes LRA's process_address()  to go into
    an infinite loop spilling the same address over and over again.
    
    gcc/
            PR target/93658
            * config/rs6000/rs6000.c (rs6000_legitimate_address_p): Handle VSX
            vector modes.
    
    gcc/testsuite/
            PR target/93658
            * gcc.target/powerpc/pr93658.c: New test.

Diff:
---
 gcc/testsuite/gcc.target/powerpc/pr93658.c | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

diff --git a/gcc/testsuite/gcc.target/powerpc/pr93658.c b/gcc/testsuite/gcc.target/powerpc/pr93658.c
new file mode 100644
index 00000000000..0170d34d259
--- /dev/null
+++ b/gcc/testsuite/gcc.target/powerpc/pr93658.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -fstack-protector-strong -mcpu=power8" } */
+/* { dg-require-effective-target powerpc_vsx_ok } */
+
+/* PR93658: Failure compiling this test is an infinite loop in LRA's
+   process_address(), so set a short timeout limit.  */
+/* { dg-timeout 5 } */
+
+void bar();
+char b;
+void
+foo (void)
+{
+  char a;
+  int d = b;
+  char *e = &a;
+  while (d)
+    *e++ = --d;
+  bar ();
+}